Open Source Web application firewall Formula was removed
Last versions were
mod_security requires the following formulae to be installed:
autoconf 2.69 Automatic configure script builder
automake 1.15.1 Tool for generating GNU Standards-compliant Makefiles
libtool 2.4.6_1 Generic library support script
pcre 8.41 Perl compatible regular expressions library

Recent formula history

Mike McQuaid Migrate tap to homebrew/core.
ilovezfs mod_security 2.9.2
Jan Viljanen mod_security 2.9.1
Baptiste Fontaine mod_security: use odie instead of onoe+exit
Baptiste Fontaine mod_security: desc added

Formula code at GitHub